A mobile terminal, such as a mobile phone, generally has applications preinstalled therein. In an operating system, such as an ANDROID system, a preinstalled application is stored in a system partition of a NAND Flash (generally referred to as a flash memory). When a user starts a mobile phone for the first time, or restores a mobile phone to factory defaults, the preinstalled application is installed using system-level permission by default, and the user cannot uninstall the preinstalled application as required; besides, a version of a preinstalled application is generally upgraded very soon, and there is a time interval between a manufacturer building a preinstalled application into a mobile terminal and a user obtaining a product. As a result, when using the mobile terminal, the user generally receives a prompt message indicating that the application needs to be upgraded. In this case, once the user updates and upgrades the application, the upgraded application coexists with the preinstalled earlier-version application that cannot be uninstalled, and therefore more space in the NAND Flash is occupied and a waste of a space resource is caused.